Your theory doesn’t really hold up, because with that explanation you’d expect an abundance of trans woman in many other traditionally male dominated fields as well.
The more likely explanation is that both being trans and being heavily invested in Linux to the point you visit conferences correlate to being neurodivergent.
That said the other part is true: there are probably many women who’s talent and interest in STEM was never properly nurtured. From my personal experience in the field I can say that my female colleagues are just as competent as my good male colleagues, but I’m yet to encounter a grossly incompetent female colleague. My theory is that woman need higher dedication and talent to overcome the adversary that unfortunately still exists, resulting in a higher skill floor.
In terms of memory usage it’s a waste. But in terms of performance you’re absolutely correct. It’s generally far more efficient to check is a word is 0 than to check if a single bit is zero.